The present invention is directed to a composition and method for treating tumors. More specifically, the present invention is directed to the treatment of tumors involving administration of certain rosin extracts including abietic acid, other resin acids, and their derivatives.
Traditionally, tumors have been treated by surgery, radiation, chemotherapy, or a combination of any of these treatments. Recognition that malignant cells tend to spread systemically through the body has resulted in recent emphasis on chemotherapeutic treatment to attack such tumor cells. However, chemotherapy administration is, at the very least, extremely debilitating, while toxicity continues to be a difficult problem. Additionally, difficulties have been encountered with selectivity of action by chemotherapeutic agents against certain malignant cells, while problems of providing a suitable delivery mechanism of such drugs have also been experienced. Accordingly, the search continues for improved anti-cancer treatments which minimize toxicity, improve selectivity of action (i.e. attack only malignant tumors), and enhance delivery of active agents to the situs of such malignant tumors and cells.
For example, U.S. Pat. No. 4,193,931 discloses 7-(substituted indanyl or naphthyl)-3-methyl-octa-2,4,6-triene derivatives which are useful as anti-tumor agents. U.S. Pat. No. 4,786,496 relates to an immunopotentiator having anti-tumor activity which is derived from marine chlorella. Ref. Zh. Khim 1971, Abstr. No. 8Zh623 (CA76: 141080g (1972)) states that certain specific alkylating derivatives of abietic acid, dehydroabietic acid and 6-hydroxyabietic acid exhibited antitumor activity against certain sarcomas. At the same time, other alkylating derivatives of these acids were found to be very toxic, while still other alkylating derivatives were documented as exhibiting no or very weak anti-tumor activity. Pharmaceutical Chemistry Journal Volume 6, No. 10 (1972), pages 647-650 also documents these specific test results.